This invention relates to spray gun systems and to an air valve useful therewith.
One type of spray gun system employs a gun that sprays resin and catalyst at a workpiece and an air-operated chopper for chopping fiberglass and projecting it onto the workpiece. The spray gun typically utilizes a mechanical linkage between a trigger and each of two valve opening members to draw back the valve members and allow pressured resin and catalyst to be sprayed from the gun. An air hose typically extends to the chopper, and an air valve near the chopper must be opened to begin the chopping and deployment of fiberglass or other wire material. A workman typically pulls the trigger with his right hand to begin spraying resin and catalyst, and a short while later opens the air valve to the chopper with his other hand to begin spraying fibers at the workpiece. The operation is often cumbersome because of the need for utilizing both hands to begin spraying, the need for continually applying large forces to the trigger to overcome a spring that will return the valve members to a closed position, and the need to use the left hand to close the chopper valve at the end of spraying. Two separate valve assemblies are typically used to spray the resin and fiberglass, with the two assemblies angled towards each other so that the two sprays cross and merge a short distance in front of the gun. The use of two separate valve assemblies, each with its own linkage and material-holding tube, increases the complexity and size of the spray gun.